The present invention relates to an apparatus for recording and/or reproducing a disc-shaped recording medium, which records or reproduces an information signal by using an optical disc such as a CD (compact disc) or a CD-ROM (read-only memory), a disc-shaped recording medium such as a magneto optical disc, or the like. More particularly, the invention relates to an apparatus for recording and/or reproducing a disc-shaped recording medium, which can selectively switch an operation of elevating a housing member for housing a plurality of placement members each on which a disc-shaped recording medium is placed and an operation for carrying any one of a plurality of placement members at least between a position where the placement member is housed in the housing member and a position where a disc-shaped recording medium is loaded to a recording and/or reproducing unit.
Conventionally, generally, as an example of an apparatus for recording and/or reproducing a disc-shaped recording medium, there has been provided a disc recording and/or reproducing apparatus for reproducing music, movie, or the like by using a disc-shaped recording medium such as a CD or CD-ROM. As a disc recording and/or reproducing apparatus of this kind, for example, a disc player 1 as shown in FIG. 1 is known.
The disc player 1 has the function of, for example, housing three disc cartridges 2 at once, consecutively reproducing the three discs housed in the disc cartridges 2 and reproducing music pieces recorded on discs housed in the three disc cartridges 2 in accordance with an arbitrary order. The disc player 1 comprises a changer 3 capable of housing the three disc cartridges 2, a carrying mechanism for selecting and carrying an arbitrary disc cartridge 2 between the changer 3 and a disc driving device, and a recording/reproducing mechanism for chucking the disc cartridge 2 carried by the carrying mechanism and recording or reproducing music or the like.
The changer 3 is mounted in the central part of the front face of the device body 4 and has three cartridge insertion ports 5a, 5b, and 5c on its front face. The three cartridge insertion ports 5a to 5c are arranged at predetermined intervals in the vertical direction (three-layer structure). On one sides of the cartridge insertion ports 5a to 5c, ejection buttons 6a, 6b, and 6c for ejecting the disc cartridges 2 inserted in the corresponding cartridge insertion ports 5a to 5c are provided, respectively.
The front face of the changer 3 is covered with a door 7 attached to the front side of the device body 4. On both sides of the door 7, a number of operation buttons 8 such as a power button for turning on/off the power source, a feed button, and a stop button are arranged. When the door 7 is opened to expose the front face of the changer 3 and the disc cartridges 2 are inserted from the cartridge insertion ports 5a to 5c, the three disc cartridges 2 are housed and held in predetermined positions.
Behind the changer 3, a carrying mechanism for selectively taking and carrying arbitrary one of the three disc cartridges 2 housed in predetermined positions is provided. Near the carrying mechanism, a disc reproducing device for chucking the disc as a recording medium of the disc cartridge 2 supplied by the carrying mechanism and loaded in a predetermined position, reading a sound signal or the like, and reproducing music or the like is disposed.
In the conventional disc player 1 as described above, however, three motors are used as driving sources; a motor for vertically moving a holder for selectively taking out an arbitrary disc cartridge 2 from the three disc cartridges 2 housed in cartridge housing parts in three positions, a motor for carrying a cartridge holder for holding the taken disc cartridge 2 to the disc reproducing device, and a motor for chucking the disc cartridge 2 supplied to the disc reproducing device and rotating it at predetermined speed. Since an independent motor is used for each of the operations such as ejection of the disc cartridge, carriage of the disc cartridge, and the like, there are problems such that the number of motors used is large, the whole device is heavy, and it is uneconomical.
Ditto for a disc player using a disc-shaped recording medium such as a CD in place of the above-described disc cartridge 2. The disc player of this kind is provided with a plurality of disc trays on which a plurality of CDs are placed, respectively, and a tray stocker for holding the plurality of disc trays. As driving sources of those components, total three motors are used; a motor for vertically moving the tray stocker, a motor for ejecting the disc trays held by the tray stocker from the device body and carrying a CD placed on the disc tray to the disc reproducing unit, and a motor for moving a spindle motor in the disc reproducing unit and chucking the CD. The disc player also has the three motors and, likewise, the number of motors is large.
The inventor who applies for the present invention has completed a mechanism capable of performing the above-mentioned three kinds of operations by two motors. According to the mechanism, both the operation of vertically moving the tray stocker for holding the plurality of disc trays and the carrying operation of tacking and carrying one of the disc trays held in the tray stocker can be performed by a single motor. The inventor had made efforts to realize an operation of exchanging disc-shaped recording media during recording or reproducing of a disc-shaped recording medium by using a single motor as a driving source and could have invented an exchange mechanism having such a function.
In the exchange mechanism, however, whether the disc-shaped recording medium is placed on the disc placement part of the disc tray or not has to be sensed. An optical sensor is therefore disposed inside of the front face of the device body and the presence or absence of the disc-shaped recording medium is determined according to whether light emitted from the optical sensor is interrupted or not. Since the optical sensor is disposed near the recording medium insertion port, there is a case that external light enters the device body and it causes a problem such that the presence/absence of the disc-shaped recording medium is erroneous determined due to the influence of external light.
Further, since a wiring board, operation buttons an other electronic parts mounted on the wiring board, a display panel, and the like are disposed where the optical sensor is mounted, those components interfere with the optical sensor. It brings about a problem such that designing of the disc recording/reproducing apparatus is limited.
In the exchanging mechanism, a power transmission path connecting a feed gear to be engaged with a rack formed in the disc tray and the motor for driving the feed gear so as to transmit the power is directly connected. Since the driving force of the motor is directly transmitted from the feed gear to the rack, it causes the following problem. There is the possibility that the disc tray erroneously is moved due to the rotation of the motor during recording or reproduction of the disc-shape recording medium.
The invention has been achieved in consideration of the conventional problems and an object of the invention is to provide an apparatus for recording and/or reproducing a disc-shaped recording medium, whose weight and size are reduced by decreasing the number of motors as driving sources and also whose manufacturing cost is reduced, thereby solving the problems.
Further, an object of the invention is to provide an apparatus for recording and/or reproducing a disc-shaped recording medium, which comprises a photodetector almost in a center of a position where a disc tray housed in a housing part is housed and which can detect the presence or absence of a disc-shaped recording medium by turning on or off light from the photodetector by the disc-shaped recording medium being carried without causing an erroneous decision due to an influence of external light and increase the degree of freedom in designing by reducing limitation on designing, thereby solving the problems.
Further, an object of the invention is to provide an apparatus for recording and/or reproducing a disc-shaped recording medium, capable of realizing an exchanging function with a simple structure by disconnecting the power transmitting path during recording or reproduction of a disc-shaped recording medium so as not to transmit a driving force to a feed gear, thereby solving the problems.
An apparatus for recording and/or reproducing a disc-shaped recording medium according to the invention comprises: a plurality of placement members on each of which a disc-shaped recording medium is placed; a housing unit in which the placement members are stacked and housed; an elevating mechanism for elevating the housing unit in the direction almost parallel to the stack direction of the placement members; a recording and/or reproducing unit for recording or reproducing the disc-shaped recording medium; a carrying mechanism for carrying at least one of the plurality of placement members between a position where the placement member is housed in the housing unit and a position where the disc-shape recording medium placed on the placement member is loaded to the recording and/or reproducing unit; a driving source for driving both the carrying mechanism and the elevating mechanism; and a switching mechanism for selectively supplying a driving force from the driving source to the carrying mechanism and the elevating mechanism.
Further, an apparatus for recording and/or reproducing a disc-shaped recording medium according to the invention comprises: a plurality of placement members on each of which a disc-shaped recording medium is placed; a housing unit in which the placement members are stacked and housed; an elevating mechanism for elevating the housing unit in the direction almost parallel to the stack direction of the placement members; a recording and/or reproducing unit for recording or reproducing the disc-shaped recording medium; a carrying mechanism for carrying one of the plurality of placement members among a position where a disc-shaped recording medium can be placed or ejected to/from the placement member, a position where the placement member is housed in the housing unit and a position where the disc-shape recording medium placed on the placement member is loaded to the recording and/or reproducing unit; a driving source for driving both the carrying mechanism and the elevating mechanism; and a switching mechanism for selectively supplying a driving force from the driving source to the carrying mechanism and the elevating mechanism.
Further, an apparatus for recording and/or reproducing a disc-shaped recording medium according to the invention comprises: a plurality of placement members on each of which a disc-shaped recording medium is placed; a housing unit in which the placement members are stacked and housed; a recording and/or reproducing unit for recording or reproducing the disc-shaped recording medium; a moving mechanism for moving the recording and/or reproducing unit from a position where the disc-shaped recording medium on the placement member is lifted from the placement member and a position lower than the placement member; a carrying mechanism for carrying one of the plurality of placement members between a position where the placement member is housed in the housing unit and a position where the disc-shape recording medium placed on the placement member is loaded to the recording and/or reproducing unit; a driving source for driving the carrying mechanism; and a transmitting mechanism for interrupting transmission of a driving force from the driving source when the recording and/or reproducing unit is moved to the lifting position.